Previous studies in experimental animals and patients have suggested a circadian variation in host toxicity following administration of 5-fluorodeoxyuridine (FdUrd) although the biochemical mechanisms are not fully understood. Thymidine kinase (TK; EC 2.7.1.21), the initial enzyme in the thymidine-phosphorylation pathway, is the first enzyme in the anabolism of FdUrd. Dihydropyrimidine dehydrog...

To investigate the role of the autonomic nervous system (ANS) in the generation of the circadian blood pressure (BP) variation, the degree of impairment of the ANS was related to the results of ambulatory BP recordings in 212 patients with progressive autonomic failure due to familial amyloid polyneuropathy. On the basis of BP and/or heart rate (HR) responses to the Valsalva maneuver, 60 degree...

This study quantifies sex differences in the diurnal and circadian variation of sleep and waking while controlling for menstrual cycle phase and hormonal contraceptive use. We compared the diurnal and circadian variation of sleep and alertness of 8 women studied during two phases of the menstrual cycle and 3 women studied during their midfollicular phase with that of 15 men. Participants underw...

J-MUBA was a large-scale clinical study which, for the first time in the world, evaluated the effects of an antihypertensive drug on circadian BP variation in more than 600 patients with hypertension. Although ACE inhibitors reportedly exert equal 24-hour antihypertensive effects on daytime and nighttime BP, and -blockers are reported to have weaker effects on nighttime BP than on daytime BP. H...

BACKGROUND AND PURPOSE Acute myocardial infarction and sudden death display a circadian rhythm, with a higher risk between 6 AM and noon. Some reports suggest that stroke does not follow such a circadian variation and that hemorrhagic stroke occurs more often during the evening. METHODS A meta-analysis of 31 publications reporting the circadian timing of 11,816 strokes was performed, subdivid...

The increasing demand for improved agricultural production will require more efficient breeding for traits that maintain yield under heterogeneous environments. The internal circadian oscillator is essential for perceiving and coordinating environmental cues such as day length, temperature, and abiotic stress responses within physiological processes. To investigate the contribution of the circa...

The impact of environmental and behavioral factors on the 24-h profile of blood pressure (BP) has been well established. Various attempts have been made to control these exogenous factors, in order to investigate a possible endogenous circadian variation of BP. Recently, we reported the results of the first environmentally and behaviorally controlled laboratory study with 24-h recordings of BP ...